At least twice during the past year, illegal bookmakers came out of the shadows and into the world of baseball to pressure Paul Lo Duca into paying gambling debts, several sources have told the Daily News.

The first incident was in June 2005 when a man called the Florida Marlins to tell them Lo Duca, then with the team, owed him money, which was immediately reported to Major League Baseball, several sources familiar with the incident have said. The Marlins referred all questions about the Brooklyn-born Lo Duca to Major League Baseball.

In May, a man from Arizona, where Lo Duca was raised and his parents still live, called associates of Lo Duca’s and demanded payment for another alleged debt, and threatened to go to Shea Stadium to intimidate Lo Duca into paying.

One major league source said someone did appear at a Mets game and confronted Lo Duca from the seats behind the backstop during batting practice earlier this year. Lo Duca declined to comment through a Mets spokesman, and Mets front office personnel, security officials and NYPD officers at Shea said they did not know of such an incident.

When confronted about the demanding phone calls, Lo Duca, who signed a three-year, $18 million contract in January 2005, said he had no such debts and that the calls were actually in reference to a friend of his with gambling issues, one source familiar with the incidents said.